Hi,
following Alexander Leidinger's work [1], I've generated Doxygen documentation 
of some NetBSD internal frameworks. 

You can browse them in HTML format under:
	* UVM: http://www.netbsd-pt.org/users/rpaulo/doxygen/uvm/
	* netinet: http://www.netbsd-pt.org/users/rpaulo/doxygen/netinet/
	* netinet6: http://www.netbsd-pt.org/users/rpaulo/doxygen/netinet6/
	* netipsec: http://www.netbsd-pt.org/users/rpaulo/doxygen/netipsec/
	* net80211: http://www.netbsd-pt.org/users/rpaulo/doxygen/net80211/
	* nfs: http://www.netbsd-pt.org/users/rpaulo/doxygen/nfs/
	* libkern: http://www.netbsd-pt.org/users/rpaulo/doxygen/libkern/

Hope this helps.

[1] - http://www.leidinger.net/FreeBSD/src_docs/

-- 
Rui Paulo <rpaulo@netbsd-pt.org>